Colorblindness is a condition that affects approximately 7% to 10% of the human population. It is typically attributable to genetic makeup and at the present time there is no known cure. Usually colorblindness does not manifest as the lack of ability to see all colors, but rather manifests as the lack of ability to distinguish colors in the longer wavelengths (lower energy) portion of the visible spectrum. Accordingly, most colorblind individuals are impaired in the ability to see red and/or green colors, but can see colors associated with shorter wavelengths.
Unfortunately, color perception is increasingly required skill in modern jobs. For example, many jobs require the use of lasers for alignment or targeting. The jobs are not only in scientific fields, but also in construction, metal fabrication, farming, surveying and painting, for example.
Additionally, colorblindness impairs an individual's ability to recognize signals such as traffic signals and instrument panel warning lights. Accordingly, some countries restrict a colorblind individual's right to drive a motor vehicle and/or pilot aircraft.
Upconverting nanoparticles are phosphors that absorb light at a first wavelength and emit light at a shorter wavelength in an Anti-Stokes emission process. Many upconverting nanoparticles absorb light in the near IR range and emit light in the visible region. Upconverting nanoparticles have been synthesized using host lattices such as LaF3, YF3, Y2O3, LaPO3, NaYF4 codoped with trivalent rare earth ions such as Yb+3, Er+3, and Tm+3. The rare earth lanthanide ions doped in crystal centers of the lattice act as absorber ions and emitter ions.
Upconverting nanoparticles have been used for a number of biological assays and imaging applications as the Anti-Stokes emission of upconverting nanoparticles has good photostability under prolonged emission excitation, the emission of the upconverting nanoparticles is a wavelength(s) that is distinguishable from natural fluorescence in biological materials and the upconverting nanoparticles have low toxicity. There are few if any intrinsic biological materials that display upconversion emission, hence interference and artifacts from the biological material are minimized when data is based on emission related to upconverting nanoparticles.
In the prior art the use of upconverting nanoparticles is typically associated with putting the upconverting nanoparticle in a biological material or system to facilitate detection of a component and/or imaging.
Other applications of upconverting nanoparticles include product and/or brand authentication; improvement of efficiency of electronic devices such as improved efficiency of LED lamps, for example; and in renewable energy applications. For example, in renewable energy applications, optical nano-materials have the ability to better utilize the full spectrum of solar radiation which results in an enhanced photovoltaic energy efficiency and more effective use of solar energy.
Accordingly, the prior art has focused on the use of upconverting nanoparticles as tags or for improved efficiency in electronics and photovoltaic applications.